The transition-density matrix analysis helps in pointing out the section of structure/molecule from where the electronic transition mainly occurs.Also I found a paper which describes the relation between transition dipole moment and transition density.a) Mengtao Sun,Jianing Chen and Hongxing Xu, THE JOURNAL OF CHEMICAL PHYSICS 128, 064106 2008.

In general transition density contains information about the spatial location of the excitation.

>On Wed Sep 17 '14 9:45am, Siddheshwar Chopra wrote>-------------------------------------------------->>Dear Users,>>I wish to know about the determination of Transition density matrix. How do we extract it from the o/p data? Do we need to mention any special command to get the same? If no, then how to search for it in the o/p file? What all we can infer using it? Someone please throw some light on it.